Date of Award

5-2009

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Earth and Environmental Studies

Thesis Sponsor/Dissertation Chair/Project Chair

Gregory Pope

Committee Member

Matthew Gorring

Committee Member

Jennifer Callanan

Abstract

Late Pleistocene (-15,000 years ago) geomorphic processes in the Pinelands of southern New Jersey were investigated after odd lineations were found on an Electromagnetic Induction (EMI) survey during the construction of a runway expansion at Lakehurst Naval Air Engineering Station. These lineations roughly matched up with alternating high and low albedo lineations identified on a 1931 aerial photomosaic approximately 17 kilometer (km) south of Lakehurst Navy Base in Davensport Branch, New Jersey. These lineations were initially hypothesized to be relicts from strong katabic winds flowing off the Laurentide Ice Sheet that would have been capable of winnowing magnetic sands from nearby sediments, which contain -2% of Ti-Fe oxide-rich minerals. Other processes such as fire were also considered in the formation of the lineations.

Soil sample locations were mapped at contrasting bright (high albedo)/dark (low albedo) and magnetic/non-magnetic lineation locations. Samples were collected at 25 cm increments from the surface until reaching 75 cm and were analyzed to determine differences in mineralogy, particle size, and magnetic susceptibility between lineations at both sites. All sample locations verified bulk mineralogy of quartz on an X-Ray Diffractometer with no differences seen between lineations at either site.

Soil sample measured on a laser particle size exhibited a bimodal and unimodal distribution for a majority of samples with the largest concentration of particle size as the sand (100 to 1000 um, 0.1 to 1.0 mm) size fraction and the secondary concentration silt from the 10 to 100 um (0.01 to 0.1 mm). The statistical testing, cluster analysis, was performed based on the distribution curves and was moderately successful (between 50% and 90% of the cases) in classifying samples into lineation groups (magnetic/non- magnetic, or low/high albedo), though always with exceptions and outliers that defied explanation.

Bulk magnetic susceptibility and magnetic behavior analysis determined the samples o were weakly magnetic with a low field bulk magnetic susceptibility of 1.21 x 10-8 to 1.25 x 10-7 m3 /kg. Some alternation between magnetic and non-magnetic lineations was seen in the 25-50 cm depth range at both Lakehurst Navy Base and Davensport Branch though not always repetitive. Little to no magnetite was found in these samples, which is a common mineral byproduct of forest fire.

Based on the sedimentological results it cannot be conclusively said that these lineations are wind streaks or fire streaks. Most methodology in this study was not able to differentiate lineations. Lineations are an enigmatic feature of the relatively unexplored geomorphology of the Pine Barrens of New Jersey. The scope of this project cannot point to definitive proofs of the origins for these lineations at Lakehurst Navy Base and Davensport Branch, though wind and forest fire are promising avenues for continuing studies. The work included in this study and future research on these features will help to define the paleoenvironment of southern New Jersey, a vital link in the regional understanding of the late Pleistocene.

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